The reinforcement of rubber and other elastomers with carbon black, p-aramid pulp and other materials is well known. See for example, U.S. Pat. Nos. 4,514,541 and 4,871,004. The use of fibrids in fibrid/elastomer compositions provides a simplified and more effective way of reinforcement over previously known fiber/elastomer compositions. The use of fibrids simplifies the mixing of the reinforcer and the elastomer, said mixing usually done in conventional "rubber" mixing equipment, such as Banbury, roll mill, extruder, etc. using well-known mixing techniques. Although these fibrids can be added as a masterbatch (pre-mixed with elastomers and/or other--usually solid--ingredients), in many cases they can be added even in the form of the "never-dried" product, i.e., containing substantial amounts of moisture. In case of rubber compositions which "set" due to chemical cross linking, this moisture is usually eliminated during the processing (mixing, calendering, molding) operations. With the thermoplastic elastomers this is not the case, and it is advisable to remove most or all of the moisture from the "never-dried" product prior to its addition to the elastomer.
Some of the prior art reinforced elastomeric products exhibit high modulus at low elongation but fail at high elongation. Other reinforcements present manufacturing problems because they are difficult to blend in with the elastomer and result in directional products. Poor blending is manifested by voids and flaws in the end product. Still other agents do not provide the desired degree of modulus improvement. The present invention seeks to overcome these deficiencies.